DESCRIPTION (Adapted from Investigators Abstract): Two proteins crucial to proper B-cell development, the interferon regulatory factor (IRF) family member Pip and the ETS protein PU.1, must bind to each other and to specific DNA targets to exert their transcriptional control. PU.1 is a known oncogene and regulator of B-cell development. Members of the IRF family of proteins control processes in signal transduction, apoptosis, antiviral responses and oncogenesis. She wishes to study functional and structural aspects of their protein-protein interaction domains by an interdisciplinary approach using a combination of molecular biology and biophysical methods. First, she will ask what is the minimal protein interaction domain from Pip capable of forming ternary complexes with PU.1 and DNA. These studies will combine random and site-directed mutagenesis with an EMSA assay for complex formation and cotransfections for a functional assay. Second, she will determine what contribution each component makes to the stability of the ternary complex. These studies rely on surface plasmon resonance to determine kinetic and thermodynamic contributions from each macromolecule to the stability of ternary complexes. Finally she will use NMR to determine the solution structure of the minimal protein-protein interaction domain from Pip and a representative PEST domain from PU.1.